title: Identification of CD25+ gamma delta T cells as fetal thymus-derived naturally occurring IL-17 producers.
abstract: We previously reported that resident gammadelta T cells in the peritoneal cavity rapidly produced IL-17 in response to Escherichia coli infection to mobilize neutrophils. We found in this study that the IL-17-producing gammadelta T cells did not produce IFN-gamma or IL-4, similar to Th17 cells. IL-17-producing gammadelta T cells specifically express CD25 but not CD122, whereas CD122(+) gammadelta T cells produced IFN-gamma. IL-17-producing gammadelta T cells were decreased but still present in IL-2- or CD25-deficient mice, suggesting a role of IL-2 for their maintenance. IFN-gamma-producing CD122(+) gammadelta T cells were selectively decreased in IL-15-deficient mice. Surprisingly, IL-17-producing gammadelta T cells were already detected in the thymus, although CD25 was not expressed on the intrathymic IL-17-producing gammadelta T cells. The number of thymic IL-17-producing gammadelta T cells was peaked at perinatal period and decreased thereafter, coincided with the developmental kinetics of Vgamma6(+) Vdelta1(+) gammadelta T cells. The number of IL-17-producing gammadelta T cells was decreased in fetal thymus of Vdelta1-deficient mice, whereas Vgamma5(+) fetal thymocytes in normal mice did not produce IL-17. Thus, it was revealed that the fetal thymus-derived Vgamma6(+) Vdelta1(+) T cells functionally differentiate to produce IL-17 within thymus and thereafter express CD25 to be maintained in the periphery.
authors.affiliation: Division of Host Defense, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Shibata
authors.forename: Hisakata
authors.initials: H
authors.lastname: Yamada
authors.forename: Risa
authors.initials: R
authors.lastname: Nakamura
authors.forename: Xun
authors.initials: X
authors.lastname: Sun
authors.forename: Momoe
authors.initials: M
authors.lastname: Itsumi
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Yoshikai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002454:Cell Differentiation / Q000276:immunology; D002478:Cells, Cultured; D005333:Fetus / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D007113:Immunity, Innate; D007371:Interferon-gamma / Q000096:biosynthesis; D020381:Interleukin-17 / Q000096:biosynthesis*; D053645:Interleukin-2 Receptor alpha Subunit / Q000096:biosynthesis*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D010537:Peritoneum / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000096:biosynthesis*; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000196:embryology / Q000276:immunology* / Q000378:metabolism
chemical_list: D020381:Interleukin-17; D053645:Interleukin-2 Receptor alpha Subunit; D016692:Receptors, Antigen, T-Cell, gamma-delta; D007371:Interferon-gamma